Ethyl 3-(difluoromethyl)-5-methoxy-2-nitropyridine-6-carboxylate
Ethyl 5-(difluoromethyl)-4-methoxy-2-nitropyridine-3-carboxylate
Ethyl 5-(difluoromethyl)-4-methoxy-3-nitropyridine-2-carboxylate
Ethyl 6-(difluoromethyl)-4-methyl-2-nitropyridine-3-acetate